Info from: Harry’s Bridges
The bridge was built in 1866, repaired in 1887, 1892, 1925, 1938, 1954-55, and 1977, renovated in 1989 and 2001. It is a two span Town Lattice truss 460 feet long spanning the Connecticut River. It is located just off SR 12A in Cornish, New Hampshire to Windsor, Vermont. Directions: Follow SR 12A north about 7 miles from SR 11/SR 103 west of Claremont 0.5 mile past junction of Cornish City Road and just left on the west side of SR 12A. The first bridges at this site were uncovered. The first bridge at this site was completed on October 31, 1796 at a cost of $17,099.27. It was lost to a fresher in 1824 and replaced with a toll bridge in 1824. It too was lost to a fresher in 1849. The third bridge also a toll covered bridge and was built in 1849. It was also lost to a fresher in 1866. The current bridge was built at a cost of $9,000.00. The repairs in 1887, 1892, 1925, 1936 and 1938 cost $8,000.00. In 1954-55 repairs were made to the pier, floor, siding and roof replaced by the New Hampshire Highway Department.In 1977 the State of New Hampshire repaired flood and ice damage at a cost of $25,000.00. On July 2, 1987, the bridge was closed for restoration, and was reopened on December 8, 1989, at a cost of $4,650,000.00 of which New Hampshire contributed $4,450,000.00 and Vermont $200,000.00. During this restoration, about half of the floor members, the upper cord over the center pier, and the lower chord were replaced with glue-laminated yellow pine timbers, new floor joists and Douglas fir flooring was installed along with new pine siding and a galvanized steel roof with spruce rafters. This is the second longest wooden covered bridge in the United States (the longest is the 458 feet long Medora Covered Bridge in Indiana) and the longest two span covered bridge in the world. The bridge rests on large mortared granite block abutments with wing walls with poured concrete and one pier with mortared large granite blocks rounded on the upstream side, and poured concrete at the base. The bridge is covered with dark weathered tongue and groove pine boarding on the sides to the eaves, and also covers the portals. There are eighteen non-opposing small window openings with small roofs above them, along each side. The deck consists of longitudinal thick Douglas fir planking and a white painted galvanized steel roof. The bridge is also known as the Cornish, Windsor and Windsor-Cornish Bridge. The American Society of Civil Engineers designated it as a National Historic Civil Engineering Landmark in 1970. The bridge was listed on the National Register of Historic Places on November 21, 1976.